Equivalent expression of TLR8 by neonatal and adult APCs. Neonatal cord or adult peripheral blood was stained with a PE-conjugated anti-TLR8 mAb prior to flow cytometry. Monocytes (CD14⁺) and mDCs (lin1^–/HLA-DR⁺/CD11c⁺) were identified as described in “Materials and methods.” Representative histograms (open, isotype control; filled, PE-conjugated anti–human TLR8 mAb) depicting newborn monocytes (A) and mDCs (B) as well as adult monocytes (C) and mDCs (D) are shown. The expression index for TLR8 was calculated as the product of median fluorescent intensity and percent positivity. A composite analysis for expression of TLR8 in monocytes (E) and mDCs (F) reveals equivalent expression in neonatal and adult cells. Data represent means ± SEM. Statistical analysis indicates no significant differences in TLR8 expression; n = 3.